1. Field of the Invention
The present invention pertains to amplification of motion such as vibration motion, and particularly to amplification of motion caused by a piezoelectric diaphragm or the like.
2. Related Art and Other Considerations
Piezoelectric diaphragms have been employed in various types of pumps and actuators. As is well known, a piezoelectric material is polarized and will produce an electric field when the material changes dimensions as a result of an imposed mechanical force. This phenomenon is known as the piezoelectric effect. Conversely, an applied electric field can cause a piezoelectric material to change dimensions.
One exemplary piezoelectric diaphragm, known as a ruggedized laminated piezoelectric or RLP™, has a central piezoelectric wafer which is laminated to a stainless steel substrate and preferably also has an aluminum cover laminated thereover. Examples of such RLP™ elements, and in some instances pumps employing the same, are illustrated and described in one or more of the following: PCT Patent Application PCT/US01/28947, filed 14 Sep. 2001; U.S. patent application Ser. No. 10/380,547, filed Mar. 17, 2003, entitled “Piezoelectric Actuator and Pump Using Same”; U.S. patent application Ser. No. 10/380,589, filed Mar. 17, 2003, entitled “Piezoelectric Actuator and Pump Using Same”, and U.S. patent application Ser. No. 11/279,647 filed Apr. 13, 2006, entitled “PIEZOELECTRIC DIAPHRAGM ASSEMBLY WITH CONDUCTORS ON FLEXIBLE FILM”, all of which are incorporated herein by reference.
The displacement of a ruggedized laminated piezoelectric, while large compared to other piezoelectric devices, is still small in relation to the diameter of a pumping chamber in which it can be employed. Hence, compression ratios are still small, e.g., in a range on the order of 1.1 to 1.0, for example. An increased stroke for the piezoelectric diaphragm would facilitate an increased compression ratio.
What is needed, therefore, and an object of the present invention, are apparatus, method, and technique for achieving motion amplification of a piezoelectric element.